scholarly journals Dynamic optimization of methanol synthesis section in the dual type configuration to increase methanol production

2019 ◽  
Vol 74 ◽  
pp. 90
Author(s):  
Samane Masoudi ◽  
Mohammad Farsi ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Dynamic Optimization ◽  
Methanol Synthesis ◽  
Catalyst Deactivation ◽  
Dynamic Condition ◽  
Production Capacity ◽  
Operating Conditions ◽  
Second Step ◽  
Methanol Production ◽  
Equilibrium Conversion ◽  
Plant Data

The main object of this research is dynamic modeling and optimization of the methanol synthesis section in the dual type configuration considering catalyst deactivation to improve methanol production capacity. In the methanol unit, deactivation of CuO/ZnO/Al2O3 catalyst by sintering and low equilibrium conversion of reactions limit the production capacity, and changing operating temperature is a practical solution to overcome the production decay. In the first step, the considered process is modeled based on the mass and energy balance equations at dynamic condition. To prove the accuracy of developed model, the simulation results are compared with the plant data at the same operating conditions. In the second step, a dynamic optimization problem is formulated, and the optimal trajectories of manipulated variables are determined considering methanol production rate as the objective function. Finally, the performance of optimized process is compared with the conventional system at the same design conditions. The results show that operating at the optimal conditions increases methanol production capacity about 6.45%.

Multiobjective Dynamic Optimization of an Industrial Steam Reformer with Genetic Algorithms

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Ali Alizadeh ◽  
Navid Mostoufi ◽  
Farhang Jalali-Farahani
Keyword(s):  
Steady State ◽  
Dynamic Optimization ◽  
Synthesis Gas ◽  
Transition Period ◽  
Dynamic Condition ◽  
Homogeneous Model ◽  
Operating Conditions ◽  
Reactor Performance ◽  
Steady State Condition ◽  
Steam Reformer

An industrial steam reformer of a methanol plant was modeled at a dynamic condition in which a one dimensional homogeneous model was coupled with a verified kinetics from the literature. A close agreement was observed between the results of the model and industrial data from a real plant at steady state conditions. The open loop response of the system to switching between two operating conditions was investigated and shown that the produced synthesis gas during the transition period would be unsuitable for the downstream methanol converter. The genetic algorithm was then employed to perform a multi-objective dynamic optimization on the reactor performance in case of switching the feed and operating conditions. Maximization of methane conversion and minimization of a stoichiometric parameter, were considered as the two objectives' functions that were optimized for a fixed feed rate of methane to the existing unit. The results of the dynamic optimization for the specified reformer configuration were achieved after switching the operating condition. Results of the optimization showed that the produced synthesis gas would stay in its acceptable limits in terms of quality of the feed of the methanol converter and also, the final conversion of the reformer would be improved compared to the steady state condition. This procedure could be applied to the advanced process control of the methanol plant.

Carbon dioxide utilization in methanol synthesis plant: process modeling

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fereshteh Samimi ◽  
Mehrzad Feilizadeh ◽  
Seyedeh Bahareh Najibi ◽  
Mohammad Arjmand ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Carbon Dioxide ◽  
Methanol Synthesis ◽  
Operating Conditions ◽  
Inert Gases ◽  
Great Promise ◽  
Reactor Performance ◽  
Methanol Production ◽  
Carbon Dioxide Utilization ◽  
Recycle Ratio ◽  
Plant Process

AbstractThe conversion of CO2 to methanol holds great promise, as it offers a pathway to reduce CO2 level in the atmosphere and also produce valuable components. In this study, a typical methanol synthesis plant for CO2 conversion was numerically modeled. Effect of fresh feed to plant parameters (i.e., pressure and CO2 concentration) as well as the influence of recycle ratio on the reactor performance was investigated. Hence, all essential equipment, including compressor, mixer, heat exchanger, reactor, and liquid–vapor separator were considered in the model. Then, at the best operating conditions, thermal behavior and components distribution along the length and radius of the reactor were predicted. Finally, the effect of inert gases was investigated in the methanol production process and the results were compared with the conventional route (CR), which uses natural gas for methanol synthesis. The results revealed that in the absence of inert gases and by employing a recycle stream in the process, CO2 hydrogenation leads to 13 ton/day production of methanol more than CR. While in the feedstock containing 20% inert gases, which is closer to the realistic case, methanol production rate is 45 ton/day lower than CR. These findings prospect a promising approach for the production of green methanol from carbon dioxide and hydrogen.

scholarly journals Methanol Production from Pyrolysis Oil Gasification—Model Development and Impacts of Operating Conditions

2020 ◽  
Vol 10 (20) ◽  
pp. 7371
Author(s):  
Zhihai Zhang ◽  
Benoit Delcroix ◽  
Olivier Rezazgui ◽  
Patrice Mangin
Keyword(s):  
Methanol Synthesis ◽  
Process Model ◽  
High Pressures ◽  
Model Development ◽  
Operating Conditions ◽  
Production Yield ◽  
Operating Pressure ◽  
Pyrolysis Oil ◽  
Methanol Production ◽  
Operational Risks

A novel process model simulating methanol production through pyrolysis oil gasification was developed, validated, then used to predict the effect of operating conditions on methanol production yield. The model comprised gasification, syngas post-treatment, and methanol synthesis units. The model was validated using experimental data from the literature, and the results obtained by the model were consistent with reference data. The simulation results revealed that gasification temperature has a significant impact on syngas composition. Indeed, rising temperature from 400 °C to 600 °C leads to higher syngas stoichiometric number (SN) value. Conversely, SN value decreases when the gasifier temperature is above 1000 °C. Moisture content in pyrolysis oil also affects both syngas composition and SN value; an increase in the first (from 10 to 30%) leads to an increase in SN value. The Rectisol unit deeply influences the syngas SN value and methanol yield, the best results being obtained with operating conditions of −20 °C and 40 bar. Increasing the operating temperature of the methanol synthesis unit from 150 °C to 250 °C leads to an increase in the yield of methanol production; the yield decreases beyond 250 °C. Although high pressures favor the methanol production yield, the operating pressure in the synthesis unit is limited at 50 bar for practical considerations (e.g., equipment price, equipment requirements, or operational risks).

scholarly journals Optimization for energy consumption in drying section of fluting paper machine

2017 ◽  
Vol 21 (3) ◽  
pp. 1419-1429
Author(s):  
Shaaban Ghodbanan ◽  
Reza Alizadeh ◽  
Sirous Shafiei
Keyword(s):  
Process Parameters ◽  
Heat Recovery ◽  
Production Capacity ◽  
Inequality Constraints ◽  
Optimization Method ◽  
Energy Performance ◽  
Operating Conditions ◽  
Paper Machine ◽  
Recovery Performance ◽  
Drying Section

Non-linear programming optimization method was used to optimize total steam and air consumption in the dryer section of multi-cylinder fluting paper machine. Equality constraints of the optimization model were obtained from specified process blocks considering mass and energy balance relationships in drying and heat recovery sections. Inequality constraints correspond to process parameters such as production capacity, operating conditions, and other limitations. Using the simulation, the process parameters can be optimized to improve the energy efficiency and heat recovery performance. For a corrugating machine, optimized parameters show the total steam use can be reduced by about 11% due to improvement of the heat recovery performance and optimization of the operating conditions such as inlet web dryness, evaporation rate, and exhaust air humidity, accordingly total steam consumption can be decreased from about 1.71 to 1.53 tonnes steam per tonne paper production. The humidity of the exhaust air should be kept as high as possible to optimize the energy performance and avoid condensation in the pocket dryers and hood exhaust air. So the simulation shows the supply air should be increased by about 10% to achieve optimal humidity level which was determined about 0.152 kgH2O/(kg dry air).

scholarly journals Simulation study of an auto-thermal double-membrane reactor for the simultaneous production of hydrogen and methanol: comparison of two different hydrogen redistribution strategies along the reactor

2017 ◽  
Vol 19 (2) ◽  
pp. 115-124
Author(s):  
Farhad Rahmani ◽  
Mohammad Haghighi ◽  
Pooya Estifaee ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Methanol Synthesis ◽  
Membrane Reactor ◽  
Synthesis Process ◽  
Pure Hydrogen ◽  
Heterogeneous Model ◽  
Double Membrane ◽  
Methanol Production ◽  
Current Configuration ◽  
Production Of Hydrogen ◽  
Counter Current

Abstract In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-thermal methanol synthesis process, the effect of two different hydrogen redistribution strategies along a double-membrane reactor has been considered. A steady-state one-dimensional heterogeneous model was developed to compare two strategies applied in the operation of the auto-thermal methanol synthesis. It was found that the counter-current configuration exhibited the better performance compared to the reactor operated in the co-current mode from both the economic and environmental points of view. This superiority is ascribed to the establishment of a more favourable temperature profile along the reactor and also more hydrogen extraction from the reaction zone. Moreover, the influence of some operating variables was investigated on the performance of the auto-thermal double-membrane reactor in the counter-current configuration. The results suggest that utilizing this configuration for pure hydrogen and methanol production could be feasible and beneficial.

Estimated costs of implementation of membrane processes for on-site greywater recycling

2011 ◽  
Vol 63 (12) ◽  
pp. 2949-2956 ◽  
Author(s):  
P. Humeau ◽  
F. Hourlier ◽  
G. Bulteau ◽  
A. Massé ◽  
P. Jaouen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Experimental Approach ◽  
Production Capacity ◽  
Operating Conditions ◽  
Fixed Costs ◽  
Recycled Water ◽  
Membrane Processes ◽  
Submerged Membrane Bioreactor ◽  
Chemical Products ◽  
The Cost

Greywater reuse inside buildings is a possible way to preserve water resources and face up to water scarcity. This study is focused on a technical-economic analysis of greywater treatment by a direct nanofiltration (NF) process or by a submerged membrane bioreactor (SMBR) for on-site recycling. The aim of this paper is to analyse the cost of recycled water for two different configurations (50 and 500 inhabitants) in order to demonstrate the relevance of the implementation of membrane processes for greywater recycling, depending on the production capacity of the equipment and the price of drinking water. The first step was to define a method to access the description of the cost of producing recycled water. The direct costs were defined as a sum of fixed costs due to equipment, maintenance and depreciation, and variable costs generated by chemical products and electricity consumptions. They were estimated from an experimental approach and from data found in literature, enabling operating conditions for greywater recycling to be determined. The cost of treated water by a SMBR unit with a processing capacity of 500 persons is close to 4.40 € m−3, while the cost is 4.81 € m−3 with a NF process running in the same conditions. These costs are similar to the price of drinking water in some European countries.

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